PANMUNJOM, SOUTH KOREA - JULY 27: North Korean soldiers look at U.S. soldiers during the 57th anniversary of signing the ceasefire agreement ceremony on July 27, 2010 in Panmunjom, South Korea. United States and South Korea are operating a joint military exercise while marking 57th anniversary of signing the ceasefire agreement of Korean War between 1950 to 1953. The exercise, first joint drill after the sinking of South Korean warship in March 2010, is taking place for four days, and has drawn condemnation from Pyongyang. (Photo by Song Kyung-Seok-pool/Getty Images)

It is “routine and defence-oriented, designed to enhance readiness, protect the region and maintain stability on the Korean peninsula”, General James D. Thurman, commander of US troops in South Korea, said in a statement.

Foal Eagle will include about 11,000 US forces along with South Korean troops in division-sized or smaller units, US authorities said.

North Korea has denounced the exercises as warmongering.

The North has taken a hostile tone with the South since its leader Kim Jong-Il died on December 17 and was replaced by his youngest son Jong-Un.

The new leader has been appointed armed forces chief and has visited several units in an apparent attempt to burnish his military credentials.

The North denied involvement but eight months later shelled a border island and killed four South Koreans.